High energy ion beam induced modifications in diamond and diamond like carbon thin films

Diamond and DLC films deposited using hot-filament chemical vapour deposition technique at various parameters were irradiated with 50 MeV Si4+ ions. The resulting microstructural changes were studied using X-ray diffraction and scanning electron microscopy. All the samples showed the development of β-SiC and hexagonal carbon phases at the expense of the diamond/DLC phase. The ERD analysis was carried out to determine the hydrogen concentration and its distribution in DLC films. The absolute hydrogen concentration in DLC samples is of the order of 1022 atoms/cm3 which gets depleted on irradiation. The DLC samples show a clear dependence of hydrogen content on the deposition parameters. (author)